Notes for Fiber Content Labeling, Comparison of Testing Methods for Fiber Content

Whether textile production or trade, the identification of textile fiber is often the first concern. What kind of raw materials, the input ratio of raw materials is often the primary parameter of textile production. In trade, in order to prevent fraud, the product should be listed in particular. Mandatory standard GB 5296.4-1998 refers to FZ/T 01053-1998, to make the latter mandatory, which makes it very important to test the composition & content of textile fiber.

The marking of fiber content is the most direct way for an enterprise to convey the raw materials of products to consumers, and it is also the promise and guarantee to the consumers. For consumers, it is the basis of understanding textile materials and properties. So what are the principles and requirements for marking fiber content and fiber name?

Labeling Principle for Fiber Content and Fiber Name

1 The fiber content is the percentage of a fiber mass in the finished product to the total fiber quantity, rather than the ratio of raw materials to materials in weaving. Because after textile printing & dyeing and other processes, the loss of different fibers is not exactly the same. In addition, from the market spot check, the fiber content also refers to the sale of finished products.

2 The fiber content is generally expressed by the common mass percentage calculated by the net dry mass combined with the nominal moisture regain. The percentage of net dry weight can be used to express the fiber content for cotton and hemp products, but it should be indicated as net dry content. In order to prevent exceeding the allowance, customers should pay attention to the conditions indicating the fiber content when testing and making the hanging plate.

3 The fiber name shall use the standard name, and comply with the relevant national standards or industry standards. For example, the natural fiber name should be the name specified in GB/T 11951, the name of chemical fiber and other fiber should be the name specified in GB/T 4146 and ISO 2076, and the chemical fiber with abbreviation should be abbreviated for short.

4 For fibers that don’t have a uniform name in national or industry standards, they may be marked as “new fibers”. If necessary, relevant parties should provide proof or verification methods of “new fibers”.

5 In the front or behind the fiber name, there can describe the morphological characteristics of the fiber, for example, polyester (seven holes), mercerized cotton. If necessary, relevant parties should provide proof or verification methods of fiber morphology characteristics.

6 There are two methods to mark the fiber content of blended products with two or more kinds of fibers: one is listed according to the decreasing order of fiber content; the second is natural fiber in front (velvet(cashmere, camel velvet), wool, rabbit hair, silk (mulberry silk, tussah silk), hemp (flax, Ramie, jute, hemp), cotton), chemical fiber behind (polyester, polyamide, acrylic, viscose, spandex, polypropylene, copper ammonia, acetate). Both of the following criteria are available:

Viscose 30%, Wool 25%, Nylon 20%, Polyester 15%, Rabbit Hair 10%

Wool 25%, Rabbit Hair 10%, Polyester 15%, Nylon 20%, Viscose 30%

7 The tolerance range of fiber content: it is normal with the range in ±1.5%, it is beyond the limit with the range more than ±5%, and Between the two above, whether or not the exceed the limit depends on the raw material of the product and the specific variety. See FZ/T01053-1998 for more.

Labeling Requirements for Fibre Content and Fiber Name

1 Each product should be affixed with a fiber content label for indicating the name and content of each fiber content in the product.

2 Each finished product should be affixed with a durability fiber content label. For products (e.g. fabric, velvet, sewing thread, socks, etc.) that have an impact on the use of durability label or are not suitable for durability labels, which can be used other forms of labels such as hanging plates.

3 For products sold in the whole box or bag and not suitable for durability labeling, fiber content labels should be provided on a unit of sale when the fiber content of each product is the same.

4 When selling the packaged product, if the fiber information of the textile product isn’t clearly visible, the fiber content of the product should be indicated on the packaging or product description.

5 A complete set of products consisting of unit products with different fiber content; or a complete set of products with the same fiber content, but each unit sold separately, each product should have its own independent fiber content label on each product.

6 If the product is not for sale to the end consumer, the content of the fiber content label is replaced by a commercial document.

7 The durable fiber content label materials should be non-irritating to the human body, should be attached to the appropriate location of the product, and ensure that the information on the label is not covered or hidden.

8 The text on the fiber content label should be clear and eye-catching. Fiber content can be labeled on the same label as other content in the instructions. Textile fiber is the main raw material of textile, many textiles are made of one kind of fiber material, and many textiles are made of two or more kinds of fiber material. The purpose of analyzing the fiber content in textiles is to judge whether the quality of the fibers used in the production can meet the processing and application requirements of this kind of textiles. With the continuous progress of textile production technology, more and more new fiber become the raw material of textiles, so the marking of fiber content and fiber name must be obtained according to the scientific test method, for example, the common fiber qualitative analysis method AATCC 20 and AATCC 20A. The following is a comparison of the testing methods of various fiber components for reference.

	Test Method / Suitable Fiber	Merits and Drawbacks
Physical   Identification   Method	Perception Method / Common Fiber	1 The operation is simple and Convenient. 2 It needs to have a general knowledge of textile fiber and rich experience & skilled technology. 3 It suitable for natural fibers and regenerated fibers, the identification of synthetic fibers is difficult sometimes.
	Density Method / Common Fiber	1 The operation is relatively simple, but the pretreatment is cumbersome, so the pretreatment should be full. 2 It is difficult to test hollow fiber and special-shaped fiber.
	Melting Method / Synthetic Fiber	1 The operation is troublesome and difficult. 2 The final melting point is difficult to see clearly and accurately. 3 It requires skilled operation skills.
	Chromatography / Synthetic Fiber	1 The characteristic is that the chromatographic band is very narrow, easy to detect. 2 It needs to be tested in a higher temperature environment. 3 It is difficult to distinguish polymers whose relative molecular weight difference is less than 10%.
	Infrared Absorption Spectroscopy / All Fibers	1 The operation is more cumbersome, which need skilled technique. 2 The accuracy of identification is high. 3 The instrument is expensive.
	Birefringence method / All Fibers	1 The operation is more cumbersome, which need skilled technique. 2 The accuracy of identification is high.
	Optical Projection Microscope Method / All Fibers	1 The operation is simple. 2 It is easier to identify natural fibers, but sometimes it’s difficult to distinguish synthetic fibers. 3 It’s difficult to distinguish deep-stained fibers.
	Electron Scanning Microscopy Method / All Fibers	1 The operation is more cumbersome, which need skilled technique. 2 The magnification is large, the picture is clear. 3 It is easier to identify natural fibers, but sometimes it’s difficult to distinguish synthetic fibers. 4 It’s difficult to distinguish deep-stained fibers. 5 The instrument is expensive.
Chemical   Identification   Method	Combustion Method / Common Fiber	1 The operation is simple and convenient and can be done anywhere at any time. 2 It requires Skilled technical and identification experience. 3 Sometimes it’s inaccurate to identify the blended yarns. 4 It can be used as a preparatory test for other test methods.
	Thermal Analysis Method / Chemical Fiber	1 Only apply to chemical fibers. 2 The operation is more cumbersome, which need skilled technique. 3 The test result is more accurate.
	Dissolution Method / Common Fiber	1 The operation is simple, but it must be carried out strictly according to the method and procedure. 2 It is difficult to distinguish when the fiber type is not clear. 3 Careful operation is required when identifying.
	Reagent Chromogenic Dyeing Method / Common Fiber	1 The operation is simple, but the modulation reagent is troublesome. 2 The samples dyed need to be pretreated. 3 It’s difficult to distinguish synthetic fibers.
	Thermal Decomposition Method / Synthetic Fiber	1 The operation is simple, convenient and fast. 2 It requires skilled skills and experience. 3 When testing, operators should wear safety glasses or plexiglass mask.

 

What is mentioned above is the general content of the content marking and testing of fiber. For more detailed analysis and testing of the fiber content, we will follow the follow-up update in the blog. Welcome your attention. If you want to know more about textile testing — construction of testing environment, interpretation of testing standards, operation of testing instruments, please search TESTEX Blog, which will bring you more professional analysis.